Method for trimming cartridge cases

ABSTRACT

A mandrel is lowered into an open end portion of a tubular metal casing. A cutting tool is moved inwardly toward the end of the mandrel at a preset rate while revolving around the mandrel at a predetermined speed. The cutting tool severs a ringlet from the open end portion of the casing and holds the severed ringlet on the mandrel until after the mandrel has been removed from the trimming site, whereupon the cutting tool is separated from the mandrel and releases the scrap ringlet for orderly disposal.

United States Eatent n 1 Bolen Feb. 4, 1975 METHOD FOR TRIMMINGCARTRIDGE- CASES Inventor: Robert J. Bolen, Port Penn, Del.

Remington Arms Company, Inc., Bridgeport, Conn.

Filed: Apr. 6, 1973 Appl. No: 348,488

Assignee:

US. Cl 82/47, 29/132, 82/702 Int. Cl B2311 l/00, B23 3/22, 821d 51/54Field of Search 29/132, 1.3; 82/47, 71-77,

References Cited UNITED STATES PATENTS 2/1946 Smiley 82/76 6/1964Manshel ..82/70.2

Primary Examiner-Andrew R. Juhasz Assistant Examiner-Leon GildenAttorney, Agent, or Firm-John H. Lewis, .lr.; Nicholas Skovran [57]ABSTRACT A mandrel is lowered into an open end portion of a tubularmetal casing. A cutting tool is moved inwardly toward the end of themandrel at a preset rate while revolving around the mandrel at apredetermined speed. The cutting tool severs a ringlet from the open endportion of the casing and holds the severed ringlet on the mandrel untilafter the mandrel has been re moved from the trimming site, whereuponthe cutting tool is separated from the mandrel and releases the scrapringlet for orderly disposal.

4 Claims, 6 Drawing Figures will PATENIEB FEB M975 SHEET 20F 5 METHODFOR TRIMMING CARTRIDGE CASES This invention relates to a machine forcutting-off or trimming metallic tubes or tubular articles and moreparticularly to a trimming device which includes means for holding thetrimmed portions of the tubes for controlled disposal.

For the sake of clarity and conciseness, it is proposed to confine thedescription of the invention to its application to machines forcutting-off the open ends of metallic tubular articles adapted to themanufacture of cartridge cases, but it will be understood that this particular adaptation is for the purpose of illustration only and that theinvention may have other similar and equivalent uses within the scope ofthe appended claims.

Cartridge cases are generally manufactured from a metal blank. The blankis formed into a cup which is annealed and then drawn to a desiredlength and wall thickness; This generally cylindrical drawn cup,hereinafter referred to as a casing, normally has one open end which,due to the manner in which the casing is formed, tends to have a roughand uneven edge. To provide a smooth, even edge and ensure that thecartridge cases formed from the casings are of uniform length, atrimming step is utilized to sever the rough, open end portions from thecasings.

Lathe-type devices have been utilized in the prior art to perform thistrimmingstep. A typical machine is dis- I closed in US. Pat. No.2,321,298, issued to Charles R. Johnson on June 8, 1943. The cartridgecase is fed into a chuck which rotates the cartridge case at high speedwhile a trimming means seversa scrap ringlet from its open end. Thecartridge case is then ejected from the chuck and a new one inserted.This procedure, requiring insertion and removal of objects in a spinningchuck, is highly time consuming and thus only adaptable to the trimmingof center fire cartridge cases.

In the high speed operations required for the production of largenumbers of rim fire cartridge cases, it is necessary that the casings betrimmed both rapidly and accurately. To accomplish this, the casings aregener' ally aligned with their open ends extending in one direction andare transported to a cutting site where a knife blade or, more often, atrim saw slices off the uneven end portion.

Due to cost and other factors, there has been an increased tendency tomanufacture cartridge cases from materials other than brass. One verypopular material has been steel. It has been found that, while casingsmade of easily machined metals, such as brass, can be easily trimmed bya trim saw, the use of such a device for casings made of less machinablemetals, such as carbon steel, results in difficult and inefficientoperation.

A trim saw is generally in the form of a high speed circular saw whichis mounted in a fixed position while rigidly held casings aretransported through the trimming site. The saw is positioned so that itwill cut each casing to the same desired length, the plane of the outbeing generally perpendicular to the longitudinal axis of the casing.However, the motion of the casings and the high rotational speed of thecutting blade cause the ringlets of metal severed from the open ends ofthe casings to be randomly propelled at high speed making collection ofmore than a small portion of the trimming scrap extremely difficult, ifnot impossible. The scrap thus tends to collect in and aroundneighboring machinery and, regardless of attempts at prevention, the

trimmed metal ringlets, or portions thereof, find their way into movingparts and between bearing surfaces.

This relatively uncontrolled disposal of trim scrap has long been viewedas an undesirable but tolerable problem in the manufacture of brasscartridge cases. Proper collection and disposal of scrap would bedesirable but, due to the low hardness and high lubricity of brass, thescrap causes little damage to bearings or other moving parts.

However, in the manufacture of'steel cartridge cases. the manner ofdisposal of scrap is of great significance. Steel has a much greaterhardness than does brass and lacks its lubricity. Pieces of steel scrapworking their way into a bearing would soon severely damage or destroyit. Moving parts could be jammed or damaged by a buildup of steel scrap.

In accordance with this invention, a novel method and machine areprovided for trimming the open end portions from metal casings wherebythe trimmed portion is held by the cutter blade after it has beensevered from the casing. The trimmed portion is removed from thetrimming site and then released so that an orderly disposal of thetrimmed portion may be effected.

It is an object of this invention to provide a metal casing trimmingmeans which may be used with either hard or soft metals.

It is another object of this invention to provide a metal casingtrimming means which permits orderly disposal of scrap.

It is a further object of this invention to provide a metal casingtrimming means having a cutter means which both severs the open endportion from the casing and holds the severed end portion for orderlydisposal.

It is an additional object of this invention to provide a method oftrimming metal casings whereby severed end portions of the casings areheld after severing, removed from the trimming site, and released fororderly disposal.

These and other objects and advantages ofthis invention can be bestdescribed with reference to the accompanying drawings, in which:

FIG. 1 is a front view of a cartridge case trimming machine inaccordance with this invention;

FIG. 2 is a side view of the trimming machine of FIG. I in a cuttingconfiguration;

FIG. 3 is a fragmentary perspective view, partially cut away, of thetrimming machine of FIG. ll;

FIG. 4 is an exploded perspective view of a trim head assembly of thetrimming machine of FIG. 1;

FIG. 5 is a side view of the trim head assembly in a raised positionwith a cutting tool thereof in a closed configuration; and

FIG. 6 is a side view similar to FIG. 5 with the cutting tool in an openconfiguration.

The tubular casing trimming method of this invention generally comprisesthe steps of positioning the casing in axial alignment with a mandrel,an open end portion of the casing being directed toward the mandrel,positioning the mandrel within the open end portion, severing a ringletfrom the open end portion of the casing, holding the ringlet on themandrel, separating the mandrel from the trimmed casing and releasingthe ringlet.

Referring now to FIGS. 1-4, a cartridge case trimming machine 11 isillustrated which may have a fixed frame I2 having a pair of upstandingsidewalls M. A metallic base I5 is supported between the sidewalls 14with a pair of oppositely positioned gibs 16 (FIG. 2) positioned incorresponding vertical grooves or ways 17 which are formed on thesidewalls 14. An operating shaft 19 is rotatably held by the sidewalls14 in a substantially horizontal orientation and may have a largeoperating wheel 20 secured at one end portion to facilitate rotation ofthe shaft 19 by connection through a belt (not shown) to an operatingmotor in a well known manner. The shaft 19 is provided with an axiallydis placed eccentric portion 19a which is operatively connected througha link 21 to the base 15. During rotation of the shaft 19, the eccentricportion 19a reciprocates between positions vertically displacedalternately above and below the axis ofthe shaft 19 so that the link 21is vertically reciprocated therewith. The base 15, being connected tothe link 21, is reciprocated along with the link 21. This verticalmotion is permitted by interaction of the gibs 16 in the vertical ways17, which also maintains the proper orientation of the base. In thismanner, vertical support is provided for the base 15 which is also thusvertically reciprocated one full cycle upon each rotation of theoperating shaft 19.

A forward portion 15a of the base 15 has a vertical opening 22 (FIG. 3)provided therein. A pair of bearings 24 rotatably support a trim headassembly 25 within the opening 22.

The trim head assembly 25, best shown in FIGS. 3 and 4, has an outershaft 26 which engages the bearings 24 between an external flange 26aand a nut 27 which is tightly fitted onto a threaded portion 26b of theouter shaft 26. An upper end portion 260 of the outer shaft 26 has apulley 29 affixed thereto to provide rotation of the outer shaft throughconnection by a belt 30 to a motor 31 (see FIG. 2) which may be attachedto the frame 12. A lower end portion of the outer shaft 26 has a pair ofdownwardly extending legs 26d formed integrally therewith.

An inner shaft 32 has an elongated cylindrical portion 32a which extendsthrough an axial opening 34 in the outer shaft 26. An enlarged lowerportion 32b of the inner shaft 32 has a pair of downwardly extendinglegs 320 formed integrally therewith. An upper end portion 32d (FIG. 2)is journaled in a bearing 35 of a lever assembly 36. A washer 37 fittedin a slot (not shown) in the upper end portion 32d of the inner shaft 32supports one end portion of a biasing spring 39 which also acts on theupper end portion 26c of the outer shaft 26 to urge the inner shaft 32upwardly therefrom.

A mandrel 40 (FIG. 4) is held in an axial bore provided in the innershaft 32 and extends downwardly therefrom. The mandrel 40 may be held inplace by a set screw 41. To accommodate the set screw, a flattenedportion 40a may be provided at a desired loca tion on the mandrel.

A conventional cutting tool 42 is preferably mounted in a tool block 44in any convenient manner, such as through the use of a set screw 45. Thetool block 44 may be attached to a tool holder 46 by a threaded fastener(not shown). A counterbalancing member 47 is provided to prevent damagewhich might otherwise be caused by the eccentricity of the mass of thetool block 44 and tool holder 46. The counterbalancing member 47preferably has the same weight and general configuration as theassembled tool holder 46 and tool block 44. Interlocking ears 46a and47a on the tool holder 46 and counterbalancing member 47, respectively,are positioned so that their respective openings 49 and 50 can bealigned with each other to permit a pin 51 to be passed through theopenings 49 and and through openings 26e in the legs 26d of the outershaft 26 to pivotably attach the tool holder 46 and counterbalancingmember 47 to the outer shaft 26. A vertical bore 51a through the pin 51is preferably provided to allow the mandrel 40 to pass through the pin51 without interference.

The tool holder 46 and counterbalancing member 47 each have anadditional pair of ears 46b and 47b, respectively, which are attached tolinks 52 by passing pins 54 through openings in each pair of ears and analigned one of a pair of apertures 55, provided in each of the links 52.The links 52 are, in turn, connected to the inner shaft 32 by pins 56passed through other of the pair of the link apertures and throughaligned openings 32e in the legs 320. An inner end portion of each link52 may be provided with a groove 52a to prevent interference with themandrel 40.

The lever assembly 36 (FIGS. 1-3) controls the motion of the inner shaft32 relative to the outer shaft 26 and has a vertical member 57 which isattached to the forward portion 15a of the base 15 by threaded fasteners59 or other suitable attachment means. An upper end portion of themember 57 serves as a fulcrum 57a for the lever assembly 36 and may bebifurcated for better securement of the lever assembly.

A pair of levers 60 and 61 and preferably pivotably attached to thefulcrum 57a by suitable fasteners such as pins 62. The levers 60 and 61are pivotably attached to an extended upper portion 35a of the bearing35 by pins 64. Suitable openings are preferably provided in the levers60 and 61 to accommodate the passage of the extended upper portion 35aof the bearing 35 therethrough.

A rear portion 610 of the lever 61 is pivotably attached to a suitablecam follower 65 which rides on a cam 66 which is mounted on theoperating shaft 19 for rotation therewith. The rear portion 61a of thelever 61 may be laterally displaced to permit proper alignment of thecam follower 65 with the cam 66. The cam follower 65 preferably has aplurality of fingers 65a which interact with the operating shaft 19 tomaintain the proper alignment of the cam follower 65 and a roller 65bwhich interacts with a camming surface 66a of the cam 66 to produce thedesired motion of the lever 61. During rotation of the operating shaft19, interaction of the cam follower 65 with the cam 66, through thelever 61, varies the position of the inner shaft 32 relative to theouter shaft 26 to control the position of the cutting tool 42 in amanner hereinafter described in detail. Thus, a proper contour of thecamming surface 660 can produce any desired motion of the cutting tool42 during each cycle of reciprocation of the base 15.

Casings 67 to be trimmed by the cartridge case trimming machine 11 maybe carried to the trimming site by a rotating table 69 mounted to theframe 12 or by other suitable carriage means well known to those skilledin the art. Means for properly feeding the casings 67 into position onthe rotating table 69 and for removing the trimmed casings 67a therefromare also well known to those skilled in the art and are not shown.

Operation of the cartridge case trimming machine 11 will now bedescribed with reference to FIGS. 1-6. The casing 67 to be trimmed istransported to the trimming site, i.e., to a position beneath andaxially aligned with bly 25 is in a position elevated from the table 69by virtue of the axis of the eccentric portion 19a being above theprincipal axis of the operating shaft 19; the orientation of the cam 66permits the inner shaft 32 to be urged by the biasing spring 39 to itsuppermost position with respect to the outer shaft 26.

As the casing 67 is being positioned at the trimming site, the trim headassembly is moved toward its necessary position to perform the trimmingoperation. It will be readily understood that the operations of the cartridge case trimming machine 11 and the rotating table 69 may becoordinated through the use of a timing belt or other means (not shown).Rotation of the operating shaft 19 lowers the base and thus the trimhead assembly 25 toward the casing 67 to be trimmed. The action of themotor 31, through the belt 30, causes the pulley 29 and the outer shaft26 to rotate at high speed. Because the outer shaft 26 isconnected tothe inner shaft 32 through the tool holder 46 and counterbalancingmember 47 and the links 52, both the inner shaft 32 and outer shaft 26as well as the entire trim head assembly 25 are rotated by the motor 31.

While the base 15 is being lowered by the motion of the eccentricportion 19a of the operating shaft 19, the cam 66 is preferably urgingthe cam follower 65 downward so that the lever 61, pivoting around thefulcrum 57a, causes the inner shaft 32 to travel downwardly at a rategreater than the outer shaft 26 compressing the biasing spring 39. Therelative downward motion of the inner shaft 32 with respect to the outershaft 26 is conveyed through the links 52 to the tool holder 46 andcounterbalancing member 47 causing them to rotate around the pin 51 inthe directions of the respective arrows 70 in FIG. 5. At the same time,the downward motion of the inner shaft 32 lowers the mandrel 40 so thatits extended end portion positions itself within the open end of thecasing 67. This helps ensure the proper alignment of the casing 67during trimming. The pivotal motion of the tool holder 46 about the pin51 causes the cutting tool 42, which, as previously indicated, israpidly rotating around the casing 67, to be moved inwardly toward thecasing so that, upon reaching the proper vertical position, it cutsthrough the casing 67 severing a ringlet 6712 from its open end portion(see FIG. 2). It will be readily apparent that by properly coordinatingthe speed of revolution of the cutting tool 42 around the casing 67 andthe rate of inward motion of the cutting tool, the cutting rate of thecartridge case trimming machine may be optimized, i.e., set at themaximum cutting rate possible for the material. As can be seen in FIGS.2 and 5, the cutting tool 42 is located at a position just beneath theextended end portion of the mandrel 40 so that, until the tool holder 46is rotated away from the mandrel 40, the ringlet 67b severed from thecasing 67 is held on the mandrel 40 by the cutting tool 42.

Through interaction of the cam 66 and cam follower 65, the relativepositions of the inner shaft 32 and outer shaft 26 causing the ringlet67b to be retained on the mandrel 40 are retained while the trim headassembly 25 is raised vertically to the position shown in FIG. 5.Meanwhile, the table 69 may rotate moving the next casing 67 to thetrimming site. Upon further rotation of the operating shaft 19, the cam66 begins to release the cam follower 65, thus permitting upward motionof the lever 61. The upward force necessary to provide this motion isproduced by the previously compressed biasing spring 39 which upwardlymoves the inner shaft 32 with respect to the outer shaft 26 and causesthe cam follower to follow the contour of the camming surface 66a forcontrolling the relative positions of the inner and outer shafts.

As the inner shaft 32 is moved upwardly by the biasing spring 39, thismotion is translated through the links 52 so that the tool holder 46 andcounterbalancing member 47 are rotated around the pin 51 in directionsopposite those indicated by the respective arrows of FIG. 5. By thismotion, the trim head assembly 25 assumes the physical configurationshown in FIG. 6. With the cutting tool 42 withdrawn from its formerposition beneath the mandrel 40, the ringlet 67!) which had been trimmedfrom the casing 67 is no longer held on the mandrel and falls therefromfor disposal. This may be accomplished by the use of several techniquesas, for example, by directing a stream of a fluid, such as air. whichwill direct the ringlet toward and into a suction apparatus of a typewell known to those skilled in the art. Alternatively, the structurecould be modified to permit the trim head assembly 25 to be horizontallydisplaced from the vicinity of the trimming site prior to the release ofthe ringlet 6717 so that the ringlet could be allowed to fall freelyinto a bin or other collection apparatus without interfering with movingparts.

In this manner, a trimming machine is disclosed which is adjustable foroptimum cutting speed and can remove scrap ringlets from even steelcartridge cases and hold the ringlet for removal from the trimming sitefor orderly and controlled disposal.

I claim:

I. A method of trimming a tubular casing having an open end portion witha trimming machine including a mandrel with an extended end and acutting tool mounted for rotation around the mandrel, said methodcomprising the steps of rotating the cutting tool at a uniform speed,positioning a casing at a trimming site in axial alignment with themandrel, moving the mandrel and rotating cutting tool toward the casingto position the extended end of the mandrel within the open end portionof said casing, moving the rotating cutting tool toward the extended endof the mandrel at a predetermined rate to sever a ringlet from thecasing and hold the ringlet on the mandrel, removing the mandrel androtating cutting tool from the casing, and moving the cutting tool awayfrom the extended end of the mandrel to release the ringlet forgravitational removal from the mandrel.

2. A method as in claim 1 wherein said casing is of a material having anoptimum cutting rate, and said uniform speed of rotation of said cuttingtool and said predetermined rate of motion of said cutting tool are setto cause the cutting tool to sever a ringlet from said casing atsubstantially the optimum cutting rate.

3. A method as in claim 1 wherein said mandrel is positioned over astream of fluid before said ringlet is released.

4. A method of trimming a plurality of tubular casings with a trimmingmachine including a vertically aligned mandrel with an extended end anda cutting tool mounted for high speed rotation around the mandrel, saidmethod comprising the steps of rotating the cutting tool at a uniformspeed, vertically aligning a plurality of casings in horizontally spacedrelation with casing, moving the cutting tool away from the extended endof the mandrel to release the ringlet for gravitational removal from themandrel, transporting a second casing to replace the first casing at thetrimming site while the mandrel and rotating cutting tool are removedtherefrom, and lowering the mandrel and cutting tool to trim the secondcasing.

1. A method of trimming a tubular casing having an open end portion witha trimming machine including a mandrel with an extended end and acutting tool mounted for rotation around the mandrel, said methodcomprising the steps of rotating the cutting tool at a uniform speed,positioning a casing at a trimming site in axial alignment with themandrel, moving the mandrel and rotating cutting tool toward the casingto position the extended end of the mandrel within the open end portionof said casing, moving the rotating cutting tool toward the extended endof the mandrel at a predetermined rate to sever a ringlet from thecasing and hold the ringlet on the mandrel, removing the mandrel androtating cutting tool from the casing, and moving the cutting tool awayfrom the extended end of the mandrel to release the ringlet forgravitational removal from the mandrel.
 2. A method as in claim 1wherein said casing is of a material having an optimum cutting rate, andsaid uniform speed of rotation of said cutting tool and saidpredetermined rate of motion of said cutting tool are set to cause thecutting tool to sever a ringlet from said casing at substantially theoptimum cutting rate.
 3. A method as in claim 1 wherein said mandrel ispositioned over a stream of fluid before said ringlet is released.
 4. Amethod of trimming a plurality of tubular casings with a trimmingmachine including a vertically aligned mandrel with an extended end anda cutting tool mounted for high speed rotation around the mandrel, saidmethod comprising the steps of rotating the cutting tool at a uniformspeed, vertically aligning a plurality of casings in horizontally spacedrelation with an open end portion upwardly directed, transporting afirst casing to a trimming site beneath the mandrel, lowering themandrel and rotating cutting tool to position the extended end of themandrel into the open end portion of the casing, moving the rotatingcutting tool toward the extended end of the mandrel to sever a ringletfrom the casing and hold the ringlet on the mandrel, lifting the mandreland rotating cutting tool from the casing, moving the cutting tool awayfrom the extended end of the mandrel to release the ringlet forgravitational removal from the mandrel, transporting a second casing toreplace the first casing at the trimming site while the mandrel androtating cutting tool are removed therefrom, and lowering the mandreland cutting tool to trim the second casing.